Brake system for vehicles



May 20, 1952 R. A. KROPP BRAKE SYSTEM FOR VEHICLES 3 Sheets-Sheet 1 Filed Aug. 20, 1949 I I I I'llll May 20, 1952 R. A. KROPP BRAKE SYSTEM FOR VEHICLES 3 Sheets-Sheet 2 Filed Aug. 20, 1949 L I I I L I l I l||||l llllllllllllwllllllllllllll I ||I|||||| ||r May 20, 1952 KROPP 2,597,109

I BRAKE SYSTEM FOR VEHICLES Filed Aug. 20, 1949 5 Sheets-Sheet 5 Z-xh Z/MM Figs order that the crawler track may be separated for dismounting. For the purpose of grippingly engaging the tires there is provided on each plate 31 an arcuate contact member 49 projecting up from the top surface of the plate and having a contact surface shaped to fit the contour of the tire.

The member 49 has generally arcuate leading and trailing edges 4| and has upstanding wall members 42 which are arranged to snugly engage the side walls of the tire (Figure 1) When the vehicle I9 is operated as a wheel type automobile, steering movement of the front wheels I4 is accomplished through a standard worm and gear steering assembly 49 (Figure 3) which is connected to the front wheel king pins 50 by a pitman arm I, a drag link 52, a tie rod 53, and a steering arm 54;

However, when the vehicle is operated as a tractor it is not possible to pivot the front wheels when the crawler tracks are in place, and steering must be effected by stopping or slowing down the crawler track on one side of the vehicle while allowing the track on the other side to propel the vehicle forwardly at its regular speed.

Thus, to convert a wheel type vehicle to a tractor, provision must be made for locking the conventional steering mechanism in position with the front wheels of the vehicle pointed directly ahead. Next, means must be provided for braking each rear wheel independently of the other wheel so that the movements of the crawler tracks can be separately controlled.

To lock the steering mechanism there is provided an inverted U-shaped locking member 51 (Figures 1 and 2) which is pinned to a shaft 58 journaled for pivoting inbearing block 59 on a forward cross member of the frame structure I2. When the shaft 58 is pivoted in one direction, the U-shaped locking member moves downwardly over a forwardly projecting arm 69 connected to the tie rod 53 and thus prevents sidewise steer- 1 ing movement of the tie rod. Since the arm 69 is disposed centrally on the tie rod, the front wheels will be locked in a position pointed directly ahead.

As best seen in Figure l, the movement of the shaft 58 and consequently the locking member 51 is controlled from the cab of the vehicle by a lever 62 pivoted from an upstanding support member GI and connected to the shaft 58 through a radius arm 63 and a tie rod 64. A spring-loaded cylinder 55 is connected between the tie rod 64 and the arm 53 and is arranged to resiliently transmit the pull of the tie rod 64 to the arm 63.

It will be readily seen that, when the tie rod is pulled to the right by the clockwise pivoting of the control rod 92, the spring will be compressed in the cylinder 65 until the resistance of the shaft 58 is overcome, at which time the shaft 58 and the locking member 51 will be pivoted into locking position. If the forwardly projecting arm 69 of the steering mechanism has not been properly centered, the locking member 51 will be resiliently pressed downwardly on the arm 69 so that, as soon as the steering mechanism is moved through the centering position, the

4 locking member 51 will be snapped into position around the arm.

The provision of the spring-loaded cylinders 55 in the locking mechanism is a particular safety feature of this invention which causes the looking member 5l'to be snapped into position and precludes the possibility of the vehicle being run ofi the crawler track by steering movement of the wheels.

When the motor vehicle I9 is operated as a wheel type of vehicle, braking is accomplished through typical mechanical brakes which may be either of the internally or externally expanding type. Separate linkages are connected to each rear Wheel, and each linkage includes a brake drum anda brake actuating rod 85 journaled ina bearing block 81 secured to the frame I2. A lever 89, which is secured to the rod 86. is pivotally connected to a brake rod 99. At its forward end the brake rod 99 is pivotally secured to an arm 92 (Figure 4) integrally formed at one end of a tubular sleeve 93. A rod 95, journaled at either end in bearings 99 secured to the frame I2, passes freely through each tubular sleeve 93. A lever 91, having a lower laterally extending foot portion 99, is secured to the rod adjacent each sleeve 93 with the foot portion 98 overhanging the arm 92 of the sleeve 93. Adjusting screws 99 are provided on each foot portion 98 for equalizing the effective length of the brake rods 99.

Movement of the rod 95 is controlled byla foot pedal I99 secured thereto. When the pedal I99 is pushed down, the rod 95 will rotate in its bearings 96 and cause each lever 91 to contact its associated arm 92 and pivot it about the rod 95. Forward movement of the arms 92 pulls the brake rods 99 forwardly and causes braking of the rear wheels. Thus, when the vehicle is operated as an automobile, both rear wheels may be braked contemporaneously through the foot pedal I99.

As previously mentioned, when the vehicle is operated as a tractor it is necessary for steering purposes to be able to brake each wheel separately and allow independent operation of the crawler track on each side of the vehicle. This is accomplished by separate hand levers I92 which have lower tubular portions I92'a-rotatably mounted on the rod 95 adjacent each sleeve 93. A slot I92'b in the tubular portion I92ais arranged to receive a laterally projecting arm 93a of the sleeve 93. The lever I92 and consequently the slot I921) will be returned to the position shown in Figure 4- by a spring I93 secured between the lever I92 and a bar I94 (Figure 2) secured across the housing of the transmission I8. Thus, when the arm I92 is rotated, the slot I921) will contact the arm 93a and cause the associated brake to be applied. However, when the sleeve 93 is rotated by the foot pedal I99, the lever I92 will not-be moved due to the fact that the arm 93a can move in the slot I92b. Since the levers I92 act independently of each other, each rear wheel can be braked separately.

The details of the power transmission I9, the mounting and operation of the tensioning wheels, the construction of the bodyportion In of the vehicle, as well as further details of the operation of the braking system and its coordination with the other mechanisms, may be found in my abovementioned parent application.

As explained in the parent application, the cab of the vehicle is so constructed that the operator can, if he desires, stand erect in the cab while operating the vehicle. For this purpose the brake levers Hi2 have been equipped with a pivotal extension member !05 which, as shown in Figure 1 in dotted lines, is arranged to be pivoted upwardly and has a strap member I01 which engages over the top portion of the lever I02 to hold the extension in upright position. Thus, when the operator is standing up and operating the tractor in this position, the brake control levers are still within easy reach of his hand.

From the foregoing description it is seen that there is provided in this invention a novel, efficient and simple braking mechanism which may be used, without modification, either when the vehicle is operated as a tractor or as a wheel type vehicle.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In a brake linkage system for steering or braking a vehicle by independently or simultaneously applying the brakes thereof, a frame, a shaft disposed transversely of said frame and journaled thereon for rocking movement with respect thereto, two sleeves rockingly mounted on said shaft and each having a lever arm extending therefrom, a separate actuating rod movable longitudinally of the frame and pivotally connected with each of said lever arms, two hand levers rockingly mounted on said shaft and having interengagement with said sleeves with a predetermined freedom of movement in the connection therebetween, for pivotally moving the same to rectilinearly move the associated actuating rods, two lever arms extending from said shaft and mounted for rocking movement therewith and each extending into position to have engaging contact with one of said lever arms, a foot pedal secured to said shaft intermediate said hand lever to pivot said shaft and simultaneously move said first lever arms through said second lever arms in a direction to longitudinally move said actuating rods without moving said hand levers, and spring means connected to each hand operated lever to return it to inoperative position.

2. In a brake linkage system for steering or braking a vehicle by independently or simultaneously applying the brakes thereof, a plurality of longitudinally movable actuating rods, two coaxial pivoted lever arms, each of said lever arms having pivotal connection with one of said rods, a separate hand-operated lever movable into contact with each pivoted lever for actuating the same to longitudinally move said rods in one direction, a shaft coaxial with said lever arms and levers, and having said lever arms and lever rockingly mounted thereon, a foot lever on said shaft, an interengaging connection between said shaft and said lever arms, to simultaneously pivot said lever arms upon operation of said foot lever, and a lost motion connection between said arms and hand levers accommodating said foot lever for operation independently of oper- 6 ation of said hand levers, and without causing movement thereof.

3. In a brake linkage system for steering or braking a vehicle by independently or simultaneously applying the brakes thereof, a plurality of longitudinally movable actuating rods, a transverse rock shaft, two coaxial lever arms, rockingly mounted on said shaft, each of said lever arms having operative connection with one of said rods, a separate hand operated lever for pivotally moving each of said lever arms and having inter-engaging connection therewith, said inter-engaging connection including a axially extending arm and slot connection having play between the arm and the slot and permitting pivotal movement of said lever arms in an actuating direction independently of said hand levers, and a foot lever coaxial with said hand levers and having engaging connection with said first levers to simultaneously pivot said lever arms independently of operation of said hand levers and without causing movement thereof.

4. In a brake linkage system for steering or braking a vehicle by independently or simultaneously applying the brakes thereof, a plurality of longitudinally movable actuating rods, a rocking shaft extending transversely of said arms, two coaxial lever arms rockingly mounted on said rocking shaft, each of said lever arms having operative connection with one of said actuating rods, a separate coaxial hand operated lever for operating each of said lever arms; an arm formed integrally with each of said lever arms and extending therefrom in axial direction, and each of said hand operated levers hav'--' ing an elongated arcuate slot receiving an associated axially extending arm, said slots being longer than the width of the associated arms, two levers secured to said shaft adjacent each of said lever arms and each having a leg portion extending into position to have contact with an associated lever arm, a foot pedal secured to said transverse shaft, for rocking said shaft, each actuating rod being movable independently of the other by an associated hand lever and both actuating rods being moved simultaneously by rocking movement of said shaft actuated by said foot lever, and spring means holding each hand operated lever in engagement with one end of an associated slot to prevent movement of said hand operated levers upon the simultaneous actuation of said rods by said foot pedal.

ROY A. KROPP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,224,826 Wiser May 1, 1917 1,334,345 Bilgore Mar. 23, 1920 1,358,730 Hartsough Nov. 16, 1920 2,094,364 Mardis Sept. -28, 1937 2,369,936 Barth Feb. 20, 1945 2,387,236 Cousino Oct. 23, 1945 2,443,331 Stewart June 15, 1948 

